KR20180052001A - Method and Apparatus for Controlling Size of TCP Windows - Google Patents

Abstract

An electronic device is disclosed. The electronic device may include at least one processor including a memory in which the application is stored and a communication circuit for communicating with the server via the base station using the radio resources of the primary cell. Wherein the at least one processor is configured to establish a TCP connection between the electronic device and the server for the application, obtain information about at least one secondary cell available from the base station, Determining a signal quality for the auxiliary cell and determining that carrier aggregation of the main cell and the at least one auxiliary cell is feasible as a result of the measurement of the signal quality, The congestion window value and the reception window value of the reception window.

Description

[0001] The present invention relates to a TCP window size control method and apparatus,

The embodiments disclosed herein relate to techniques for controlling congestion windows and receiving windows in the transmission and reception of data using TCP connections.

One way to increase the transmission rate of data in a wireless mobile communication system is to use a relatively large bandwidth. For example, in a long-term evolution (LTE), a carrier aggregation (CA) technique combining a plurality of component carriers (CC) may be used to increase the transmission or reception rate.

In recent years, licensed-assisted accessing (LTE) and enhanced licensed-assisted accessing (LTE) technologies have been introduced to increase the transmission rate by using a part of the unlicensed band as an elementary carrier. For example, a terminal accesses a network using an element carrier corresponding to a license band and receives a wireless communication service. The UE can aggregate the element carriers corresponding to the licensed band and the unlicensed band under the control of the base station and utilize them for the downlink data transmission (LAA) and the uplink data transmission (eLAA).

Transmission control protocol (TCP), on the other hand, provides connection-oriented communication services between two applications (eg servers and clients) connected to the network.

In the TCP connection, the transmission speed of the sender is largely limited by two variable values. The first is the Congestion Window (CWND) value, which is used to suppress network congestion when multiple TCP connections are present in the network. The sender can increase or decrease the congestion window value depending on whether the congestion window of the user is congested or not. The congestion window value is only managed internally and does not notify the other party of the TCP connection. The second is the value of the reception window (RWND). Basically, it is developed to control the transmission rate of the transmission end to prevent the buffer overflow at the reception end. However, since the memory technology has developed, congestion It is mainly used to determine the maximum value of the window size.

For example, a transmitting side (eg, a terminal) transmits its own receiving window value in a data segment, and the receiving side (eg, base station or server) inserts its receiving window value into the ACK segment for the corresponding segment To the transmitting side. Since the transmitter can know the data processing capability of the receiver, it determines the congestion window calculated by itself and the reception window value received from the receiver as its own transmission rate and performs data transmission. For example, if the congestion window size of the terminal is 50 KB and the reception window size acquired from the base station is 30 KB, the terminal can transmit data segments corresponding to 30 KB without ACK reception.

Generally, downlink / uplink CA-based data transmission in a wireless mobile communication system utilizing carrier aggregation (CA) is as follows. First, the terminal notifies the base station of the supportable CA combination, and the base station provides the terminal with a list of secondary cells capable of actually activating the CA based on the information sent by the terminal. This process can be referred to as "Scell addition". The auxiliary cell may be in the license band or in the license-exempt band. Thereafter, when data traffic destined for the terminal is accumulated in a buffer (downlink) or when data traffic destined for the terminal to the base station is accumulated in a buffer (uplink) at a certain level while the terminal is staying in the base station, , The base station transmits a secondary cell activation message (e.g., a control element (CE) of a media access control (MAC) layer) to a part of available secondary cells in the secondary cell list held by the terminal, ) So that downlink / uplink transmission based on CA is performed. When the buffer of the Node B or the UE becomes empty, the Node B may transmit a disable message (e.g., Scell Deactivation MAC CE) to the UE to deactivate the activated auxiliary cell.

The limitation of this CA policy is that an additional frequency band is used for transmission only when buffering is actually performed in a base station or a terminal. In other words, even if high-throughput communication through the CA is possible between the base station and the terminal, if the throughput in the upper layer is limited, a sufficient amount of traffic is not accumulated in the buffer of the base station or the terminal, .

In particular, when TCP, which uses the congestion window and the receiving window, is used as the upper layer communication protocol, the CA function using the auxiliary cell does not operate until the size of the congestion window and the receiving window becomes sufficiently large. Therefore, it may not be possible to efficiently utilize the high data throughput available through the CA.

The embodiments disclosed in this document can provide a communication method and apparatus for solving the above-mentioned problems and the problems raised in this document.

An electronic device according to an embodiment disclosed herein includes at least one processor including a memory in which an application is stored and a communication circuit for communicating with a server via a base station using radio resources of a primary cell . Wherein the at least one processor is configured to establish a TCP connection between the electronic device and the server for the application, obtain information about at least one secondary cell available from the base station, Determining a signal quality for the auxiliary cell and determining that carrier aggregation of the main cell and the at least one auxiliary cell is feasible as a result of the measurement of the signal quality, The congestion window value and the reception window value of the reception window.

In addition, a communication method of an electronic device according to an embodiment disclosed in this document includes an operation of establishing a TCP connection between the electronic device and a server using radio resources of a primary cell, The method of claim 1, further comprising: acquiring information about a secondary cell; determining signal quality for the at least one auxiliary cell; and measuring a signal quality of the at least one auxiliary cell, And changing at least one of a congestion window value and a reception window value of a TCP connection between the electronic device and the server when it is determined that carrier aggregation is possible.

According to various embodiments disclosed herein, when an available auxiliary cell exists, the terminal can preemptively control the reception window and the congestion window value, thereby inducing carrier aggregation using the auxiliary cell.

In addition, efficiency of data transmission and reception can be increased through carrier aggregation.

In addition, various effects can be provided that are directly or indirectly understood through this document.

1 shows a communication environment according to an embodiment.
2 illustrates a protocol stack of a terminal and window settings for each application according to an exemplary embodiment.
FIG. 3 illustrates a flow diagram for changing values of a reception window and a congestion window of a TCP connection according to an exemplary embodiment.
4 illustrates data reception using control of a TCP window in a downlink according to an exemplary embodiment.
FIG. 5 illustrates data transmission using control of a TCP window in an uplink according to an exemplary embodiment.
FIG. 6 illustrates a TCP window control method in various network conditions according to an exemplary embodiment.

Various embodiments of the invention will now be described with reference to the accompanying drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes various modifications, equivalents, and / or alternatives of the embodiments of the invention. In connection with the description of the drawings, like reference numerals may be used for similar components.

In this document, the expressions "have," "may," "include," or "include" may be used to denote the presence of a feature (eg, a numerical value, a function, Quot ;, and does not exclude the presence of additional features.

In this document, the expressions "A or B," "at least one of A and / or B," or "one or more of A and / or B," etc. may include all possible combinations of the listed items . For example, "A or B," "at least one of A and B," or "at least one of A or B" includes (1) at least one A, (2) Or (3) at least one A and at least one B all together.

The expressions "first," " second, "" first, " or "second ", etc. used in this document may describe various components, It is used to distinguish the components and does not limit the components. For example, the first user equipment and the second user equipment may represent different user equipment, regardless of order or importance. For example, without departing from the scope of the rights described in this document, the first component can be named as the second component, and similarly the second component can also be named as the first component.

(Or functionally or communicatively) coupled with / to "another component (eg, a second component), or a component (eg, a second component) Quot; connected to ", it is to be understood that any such element may be directly connected to the other element or may be connected through another element (e.g., a third element). On the other hand, when it is mentioned that a component (e.g., a first component) is "directly connected" or "directly connected" to another component (e.g., a second component) It can be understood that there is no other component (e.g., a third component) between other components.

As used herein, the phrase " configured to " (or set) to be "adapted to, " To be designed to, "" adapted to, "" made to, "or" capable of ". The term " configured (or set) to "may not necessarily mean " specifically designed to" Instead, in some situations, the expression "configured to" may mean that the device can "do " with other devices or components. For example, a processor configured (or configured) to perform the phrases "A, B, and C" may be a processor dedicated to performing the operation (e.g., an embedded processor), or one or more software programs To a generic-purpose processor (e.g., a CPU or an application processor) that can perform the corresponding operations.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the other embodiments. The singular expressions may include plural expressions unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art. The general predefined terms used in this document may be interpreted in the same or similar sense as the contextual meanings of the related art and are intended to mean either ideally or in an excessively formal sense It is not interpreted. In some cases, even the terms defined in this document can not be construed as excluding the embodiments of this document.

An electronic device in accordance with various embodiments of the present document may be, for example, a smartphone, a tablet personal computer, a mobile phone, a video phone, an e-book reader, Such as a desktop PC, a laptop PC, a netbook computer, a workstation, a server, a personal digital assistant (PDA), a portable multimedia player (PMP) A camera, or a wearable device. According to various embodiments, the wearable device may be of the type of accessory (e.g., a watch, a ring, a bracelet, a bracelet, a necklace, a pair of glasses, a contact lens or a head-mounted-device (HMD) (E. G., Electronic apparel), a body attachment type (e. G., A skin pad or tattoo), or a bioimplantable type (e.g., implantable circuit).

In some embodiments, the electronic device may be a home appliance. Home appliances include, for example, televisions, DVD players, audio, refrigerators, air conditioners, vacuum cleaners, ovens, microwaves, washing machines, air cleaners, set- (Such as a home automation control panel, a security control panel, a TV box such as Samsung HomeSync ™, Apple TV ™ or Google TV ™), a game console (eg Xbox ™, PlayStation ™) A dictionary, an electronic key, a camcorder, or an electronic frame.

In an alternative embodiment, the electronic device may be any of a variety of medical devices (e.g., various portable medical measurement devices such as a blood glucose meter, a heart rate meter, a blood pressure meter, or a body temperature meter), magnetic resonance angiography (MRA) Navigation system, global navigation satellite system (GNSS), event data recorder (EDR), flight data recorder (FDR), infotainment (infotainment) ) Automotive electronic equipment (eg marine navigation systems, gyro compass, etc.), avionics, security devices, head units for vehicles, industrial or home robots, automatic teller's machines (ATMs) Point of sale, or internet of things (eg, light bulbs, various sensors, electrical or gas meters, sprinkler devices, fire alarms, thermostats, street lights, A toaster, a fitness equipment, a hot water tank, a heater, a boiler, and the like).

According to some embodiments, the electronic device is a piece of furniture or a part of a building / structure, an electronic board, an electronic signature receiving device, a projector, Water, electricity, gas, or radio wave measuring instruments, etc.). In various embodiments, the electronic device may be a combination of one or more of the various devices described above. An electronic device according to some embodiments may be a flexible electronic device. Further, the electronic device according to the embodiment of the present document is not limited to the above-described devices, and may include a new electronic device according to technological advancement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronic apparatus according to various embodiments will now be described with reference to the accompanying drawings. In this document, the term user may refer to a person using an electronic device or a device using an electronic device (e.g., an artificial intelligence electronic device).

1 shows a communication environment according to an embodiment.

Referring to FIG. 1, a terminal 100 can communicate with a base station through a main cell 11 and an auxiliary cell 12. The primary cell 11 may correspond to a licensed frequency band that is exclusively accessible to the terminal 100 authenticated by the service provider. The auxiliary cell 12 may correspond to a license frequency band that can be exclusively accessed by the terminal 100 authenticated by the communication carrier similar to the main cell 11 or may be a license- unlicensed frequency band.

The terminal 100 may include a processor 110 and a communication circuit 120. In one embodiment, the processor 110 may be referred to as an application processor (AP), and the communication circuit 120 may be referred to as a communication processor (CP). The communication circuit 120 includes a first module 121 that can aggregate carriers corresponding to the main cell 11 and the auxiliary cell 12 and utilize the carriers for uplink / downlink data transmission with the base station 10. For example, the first module 121 may correspond to a cellular module 121 corresponding to LTE-A (LTE-advanced) or LTE-A Pro.

The cellular module 121 may include an antenna for transmitting / receiving a signal of a frequency band corresponding to the cellular network, an amplifier circuit for signal processing, a filter circuit, and the like. In one embodiment, cellular module 121 may be implemented as a radio frequency block included in communication circuitry 120.

 In addition, the terminal 100 may further include components such as a memory and a display, which are not shown in FIG.

The base station 10 may process data received from the terminal 100. [ The base station 10 may include one or more base stations. The base station 10 receives data through the main cell 11 or the auxiliary cell 12 and confirms the received data and transmits data to an upper layer or transmits ACK (acknowledge) or NACK (non -ACK) can be transmitted. The base station 10 may also transmit data destined for the terminal 100. The base station 10 transmits data to the terminal 100 by using the main cell 11 or the auxiliary cell 12 together with the main cell 11 and transmits the data to the terminal 100 in accordance with the ACK or NACK obtained from the terminal 100 . ≪ / RTI > Based on the bidirectional data transmission capability, the base station 10 can provide a TCP connection between the terminal 100 and the server 200.

The base station 10 may further include a control unit for controlling the overall operation of the base station 10. [ The control unit may be implemented by a plurality of processors. The control unit can perform scheduling of the terminal 100 connected to the base station 10 and allocation of available radio resources to the terminal 100. [

A TCP connection can be established between the terminal 100 and the server 200 through the base station 10. For example, when an application installed in a memory of the terminal 100 desires to perform data transmission / reception through a TCP connection, a synchronization (SYN) message between the application of the terminal requesting the data transmission and the server application having the requested data is transmitted. SYN ACK (SYN Acknowledge)? A TCP connection can be established by a 3-way handshake consisting of ACK. Once the TCP connection is established between the terminal 100 and the server 200, dependent, sequential and reliable / ordered / error-checked data transmission can be corrected. Also, the TCP connection is established when the terminal 100 determines that there is no more data to receive and explicitly sends a FIN (Finish) segment to the server 200, or when the server 200 fails to receive any data segment It can be released.

It is assumed that the terminal 100 establishes a TCP connection with the server 200 using a carrier of the main cell 11 unless there is a specific assumption. In this state, a method of controlling the reception window / congestion window to increase data transmission efficiency by increasing the usage rate of the auxiliary cell 12 is presented.

2 illustrates a protocol stack of a terminal and window settings for each application according to an exemplary embodiment.

2, a terminal includes a protocol stack 130 including a plurality of layers, a TCP window control module 140, and a plurality of applications (e.g., a first application 151 and a second application 152) .

In one embodiment, the protocol stack 130 may be a PHY (physical) layer, a MAC (media access control) layer, a RLC (radio link control) layer, a PLCP layer convergence protocol layer, and a radio resource control (RRC) layer. It is a lower layer toward the PHY layer and an upper layer toward the RRC.

In one embodiment, the TCP window control module 140 may change the size of the TCP window of some or all of the applications. For example, the TCP window control module 140 may change the size of one of the reception window (RWND) and the congestion window (CWND) of the first application (151).

In one embodiment, protocol stack 130 and TCP window control module 140 may be implemented by at least one processor, including communication circuitry 120 or communication circuitry 120. [ For example, at least one processor (e.g., processor 110) may implement the TCP window control module 140 using instructions or program code stored in memory.

In addition, applications 151 and 152 may be stored in memory. The applications 151 and 152 shown in FIG. 2 all support TCP connections, but the terminal 100 may include other applications that do not support TCP connections.

3 illustrates a flow diagram for changing the values of a receive window and a congestion window of a TCP connection according to one embodiment.

Referring to FIG. 3, in operation 301, the terminal 100 can establish a TCP connection with the server 200. The terminal 100 can perform data communication with the server 200 using the carrier wave of the main cell 11. [

In operation 303, the terminal 100 may obtain a list of CAs capable of auxiliary cells. In one embodiment, operation 303 may be performed before operation 301 in advance. For example, the base station 10 may transmit a terminal compatibility query message (e.g., UE Capability Inquiry) of the RRC layer to the terminal 100 attempting to access the base station 10. Upon receiving the message, the terminal 100 can transmit a CA combination that the terminal 100 can support to the base station 10 through the UE capability information (e.g., UE Capability Information) of the RRC layer. For example, the terminal 100 can transmit frequency information (e.g., band and / or channel information) of each CA combination to the base station 10 when there are five possible combinations of CA combinations. In this case, since the terminal 100 is already connected to the base station 10 through the main cell 11, it is possible to provide a list of CA capable auxiliary cells 12 with respect to the main cell 11 to the base station 10 have.

The base station 10 receives the list of the CA capable auxiliary cells 12 from the terminal 100 and transmits the list of the CA capable auxiliary cells 12 to the terminal 100 through the RRC connection reconfiguration You can pass a list of auxiliary cells. For example, if the auxiliary cell capable of CA by the terminal 100 is Scell # 1, Scell # 2, Scell # 3, Scell # 4 and Scell # 5, Scell # 1 and Scell # 4 can be acquired as a list of CA capable auxiliary cells. The terminal 100 may store a list of auxiliary cells received from the base station 10. [

When the terminal 100 acquires a list of auxiliary cells available to the CA from the base station 10, the terminal 100 can continuously monitor whether the auxiliary cells included in the list are actually available in the uplink / downlink. For example, in operation 305, the terminal 100 may measure the connection quality of the auxiliary cell. For example, the UE 100 may continuously or periodically measure parameter values indicating connection quality such as RSRP, RSRQ, and RSSI for a frequency band (e.g., a channel) corresponding to the auxiliary cell. The parameters indicating the connection quality may be variously present in addition to the above examples.

In operation 307, the terminal can determine whether it is possible to activate the auxiliary cell for the CA based on the measurement result of the connection quality. For example, when the parameter value of the measured connection quality is maintained (measured) above a predetermined threshold value for a predetermined time or longer, the terminal 100 can determine that the auxiliary cell can be used for the CA.

In one embodiment, the terminal 100 may receive a monitoring command for the auxiliary cells from the base station 10. In this case, the UE can directly measure the connection quality of the corresponding auxiliary cells. However, since the terminal 100 can not directly measure the connection quality of the auxiliary cells when the base station 10 does not set the monitoring setting to the terminal 100, the terminal 100 can use the communication with the base station 10 The connection quality of the auxiliary cell can be estimated based on the connection quality measured in the primary cell channel, i.e., the primary cell 11. For example, when the main cell 11 and the auxiliary cell 12 are served by the same base station and the auxiliary cell 12 corresponds to the license-exempted band, the radio wave reach range of the main cell 11 existing in the license band is relatively The connection quality of the auxiliary cell 12 is higher than the connection quality of the auxiliary cell 12 existing in the license-exempt band having a high frequency (for example, 2.4 GHz or 5 GHz) Can be estimated to be low.

If it is determined that the auxiliary cell can be activated, the terminal 100 can change the value of at least one of the reception window and the congestion window of the TCP connection in operation 309. [

In one embodiment, the terminal 100 may increase the size of the receive window and / or the congestion window in consideration of the expected amount of bandwidth increase when the auxiliary cell is activated. For example, the UE 100 increases the size of the reception window or the congestion window of the TCP connections in proportion to the downlink or uplink bandwidth, which is increased when the auxiliary cell is activated, . For example, when the terminal 100 receives the available auxiliary cell information and immediately measures the connection quality of the auxiliary cell, if it is expected to increase the transmission capacity by about 50% of the transmission rate through the main cell, The size of the window and the congestion window can be increased by about 50% compared to the point of time.

Also, in one embodiment, the terminal 100 may increase the size of the receive window and / or the congestion window in consideration of the channel congestion of the auxiliary cell. For example, when the channel of the auxiliary cell usable in the CA exists in the license-exempt band and the channel is shared with other wireless communication technologies, the congestion window or the reception You can also determine the amount of window growth. For example, when there are other electronic devices using Wi-Fi in the frequency band used in the auxiliary cell, the RSSI value measured by the AT 100 or the NAV (NAV) obtained by decoding the Wi- Network Allocation Vector) can be used to estimate channel congestion. In one embodiment, the higher the congestion degree of the measured or estimated channel congestion, the smaller the increase in TCP receive window and congestion window size can be set.

According to the embodiment disclosed in this document, the terminal 100 can not determine the TCP reception window and the congestion window at the time when the actual base station 10 activates the auxiliary cell but the auxiliary cell is registered in the terminal 100, As shown in FIG. Generally, the base station 10 activates the auxiliary cell 12 when the downlink buffer of the subscriber station 10 or the uplink buffer of the subscriber station 100 is stacked over a predetermined reference level and the throughput increases beyond a predetermined value. If the terminal 100 determines that the auxiliary cell registered in the terminal 100 is available for carrier aggregation, if the congestion window (uplink) or the reception window (downlink) of the TCP connections is preliminarily increased, The probability of transmitting the data segment using a higher congestion window value is increased, which increases the likelihood that the data segment is quickly accumulated in the buffer of the terminal (uplink) or the base station (downlink). Therefore, the possibility that the base station 10 utilizes the auxiliary cell for downlink / uplink transmission based on the frequency aggregation also increases, and as a result, the downlink / uplink throughput experienced by the terminal 100 increases and the use efficiency of the given radio channels also increases You can go up together. Hereinafter, transmission and reception of data according to various embodiments in the downlink and uplink will be described with reference to FIGS. 4 and 5. FIG.

4 illustrates data reception using control of a TCP window in a downlink according to an exemplary embodiment. In the description of FIG. 4 and FIG. 5, description overlapping, corresponding to, or similar to the above description may be omitted.

Referring to FIG. 4, in operation 401, a TCP connection between the terminal 100 and the server 200 can be established.

In operation 403, the terminal 100 may receive data from the server 200 via the main cell 11. [

In operation 405, the base station 10 may register an available auxiliary cell to the terminal 100. This process may correspond to operation 303 of FIG.

In operation 407, the terminal 100 may increase the size of the receiving window. For example, when the terminal 100 measures or estimates the connection quality of the registered auxiliary cell and uses the CA through the auxiliary cell, if the data transmission rate is expected to increase, the size of the receiving window can be increased.

At operation 409, information about the size of the increased receiving window may be communicated to the server 200. Since the size of the receiving window of the terminal 100 has increased, the server 200 can increase the amount of data transmitted to the terminal 100 in operation 411.

However, since the base station 10 transmits data to the terminal 100 using only the carrier wave of the main cell 11, if the amount of data to be transmitted from the server 200 increases, in operation 413, The data accumulated in the link buffer increases. The base station 10 may decide to activate the auxiliary cell in operation 415 if the data increases in the downlink buffer by a predetermined reference or more. From this point on, the base station 10 can transmit data to the terminal 100 using the main cell 11 and the auxiliary cell 12. In operation 416, the base station 10 may transmit a supplementary cell activation message to the terminal 100 indicating that the supplementary cell is activated.

In operation 417, the terminal 100 can receive data from the server 200 through the carrier aggregation of the main cell 11 and the auxiliary cell 12. [

FIG. 5 illustrates data transmission using control of a TCP window in an uplink according to an exemplary embodiment.

Referring to FIG. 5, in operation 501, a TCP connection between the terminal 100 and the server 200 can be established.

In operation 503, the terminal 100 may transmit data to the server 200 via the main cell 11. [

In operation 505, the base station 10 may register an available auxiliary cell to the terminal 100. This process may correspond to operation 303 of FIG.

In operation 507, the UE can increase the size of the congestion window if it is determined that the uplink carrier aggregation using the auxiliary cell is possible, based on the measurement / estimation result of the signal quality of the registered auxiliary cell. Unlike in FIG. 4, the size of the congestion window is a value that the terminal 100 internally knows and is not transmitted to the server 200.

If the size of the congestion window increases, the terminal 100 may increase the amount of data transmission in operation 509. [ However, since the terminal 100 transmits data using the carrier wave of the main cell 11, the data of the uplink buffer is increased in operation 511. [ The terminal 100 may send a butter status report to the base station 10 at operation 512.

Accordingly, when the BS 100 receives information indicating that the uplink buffer of the MS has increased by a certain level or more through receiving the buffer status report message periodically or aperiodically transmitted to the BS 10, At operation 513, it may be determined to activate the auxiliary cell. In operation 514, the base station 10 may transmit a supplementary cell activation message indicating that the supplementary cell is activated to the terminal 100. When the auxiliary cell is activated, the terminal 100 can transmit data using both the main cell and the auxiliary cell in operation 515.

FIG. 4 corresponds to an embodiment of changing the reception window to derive a CA in the downlink, and FIG. 5 corresponds to an embodiment of changing the congestion window to derive a CA in the uplink. The CA may be supported only in some of the uplink and downlink depending on the BS or the MS. For example, CA may be supported in the downlink, but CA may not be supported in the uplink. An embodiment related to this will be described with reference to Fig.

FIG. 6 illustrates a TCP window control method in various network conditions according to an exemplary embodiment. 6 may be understood to be performed after operation 307 of FIG.

If it is determined in operation 307 of FIG. 3 that activation of the auxiliary cell is possible for the CA, the terminal 100 may determine whether both CAs are supported in the uplink and the downlink in operation 601. If all CAs are supported, the terminal 100 may increase both the received window value and the mixed window value at operation 603. [ If only the downlink CA is supported, the terminal 100 may increase the value of the reception window associated with the downlink at operation 605. Although not shown in FIG. 6, if only the uplink CA is supported, the terminal 100 may increase the value of the congestion window associated with the uplink. (See Fig. 5)

In operation 607, the terminal 100 can transmit and receive data according to the changed window value. As described in FIGS. 4 and 5, the value of the properly modified receive / congestion window can lead to the activation of the CA, i.e., the auxiliary cell, to increase the data transmission / reception efficiency.

Operations 609 and 611 may be understood as operations after the CA is activated. For example, in the state where data is transmitted / received through carrier aggregation after activation of the auxiliary cell, the activation auxiliary cell or the activatable auxiliary cell may not be present due to a change of the network environment or movement of the terminal 100 have. In operation 609, the terminal 100 may determine whether or not such an active (enabled) auxiliary cell exists.

If the active (enable) auxiliary cell no longer exists, if the increased reception / congestion window value is maintained, the buffer may not be able to handle the traffic, resulting in transmission delays or data loss. Accordingly, the terminal 100 may reduce at least one of the reception window value and / or the congestion window value again in operation 611. [ For example, the base station 10 transmits a command for deactivating the auxiliary cell activated (e.g., Scell deactivation MAC CE) to the terminal 100, or the connection quality of the auxiliary cell activated by the terminal 100 itself is degraded (For example, decrease in RSRP / RSRQ and increase in BLER in auxiliary cell, increase in channel congestion in auxiliary cell, increase in number of failure in clear channel assessment, etc.), and if terminal 100 determines that there is no active auxiliary cell By reducing the congestion window (uplink) or the receiving window (downlink) applied to the TCP connections of the mobile station by predefined equations.

The embodiments disclosed in this document are very effective even when the terminal 100 utilizes a channel in the license-exempt band for carrier aggregation. In general, the license-exempt band is a frequency resource that various wireless communication technologies can use publicly. Therefore, in the case of a wireless communication service provider providing a carrier aggregation transmission function utilizing a license-exempt band such as LTE LAA or LTE-U, it is possible to use the license-exempted band more actively for data transmission when applying the proposed scheme to the terminal, Which can cope with the data demand that explodes.

As used in this document, the term "module" may refer to a unit comprising, for example, one or a combination of two or more of hardware, software or firmware. A "module" may be interchangeably used with terms such as, for example, unit, logic, logical block, component, or circuit. A "module" may be a minimum unit or a portion of an integrally constructed component. A "module" may be a minimum unit or a portion thereof that performs one or more functions. "Modules" may be implemented either mechanically or electronically. For example, a "module" may be an application-specific integrated circuit (ASIC) chip, field-programmable gate arrays (FPGAs) or programmable-logic devices And may include at least one.

At least a portion of a device (e.g., modules or functions thereof) or a method (e.g., operations) according to various embodiments may include, for example, computer-readable storage media in the form of program modules, As shown in FIG. When the instruction is executed by a processor (e.g., processor 110), the one or more processors may perform a function corresponding to the instruction. The computer readable storage medium may be, for example, a memory.

The computer-readable recording medium may be a hard disk, a floppy disk, a magnetic media such as a magnetic tape, an optical media such as a CD-ROM, a DVD (Digital Versatile Disc) May include magneto-optical media (e.g., a floppy disk), a hardware device (e.g., ROM, RAM, or flash memory, etc.) Etc. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the various embodiments. And vice versa.

Modules or program modules according to various embodiments may include at least one or more of the elements described above, some of which may be omitted, or may further include additional other elements. Operations performed by modules, program modules, or other components in accordance with various embodiments may be performed in a sequential, parallel, iterative, or heuristic manner. Also, some operations may be performed in a different order, omitted, or other operations may be added.

And the embodiments disclosed in this document are provided for the explanation and understanding of the disclosed technical contents, and do not limit the scope of the present invention. Accordingly, the scope of this document should be interpreted to include all modifications based on the technical idea of the present invention or various other embodiments.

Claims (10)

The method according to claim 1,
Wherein the at least one processor is set to increase the value of the congestion window if the carrier aggregation is possible in the uplink from the electronic device to the server. The method according to claim 1,
Wherein the at least one processor is set to increase the value of the receive window if the carrier aggregation is possible in the downlink from the server to the electronic device. The method of claim 3,
Wherein the at least one processor is configured to transmit the value of the increased receiving window to the server. The method according to claim 1,
Wherein the primary cell corresponds to a license frequency band of the cellular network and the secondary cell corresponds to a license-exempt frequency band. The method according to claim 1,
Wherein the at least one processor is configured to perform the carrier aggregation based on the primary cell and the secondary cell when the secondary cell is activated. The method according to claim 1,
Wherein the at least one processor is configured to determine a signal quality of the auxiliary cell based on at least one of RSRP, RSRQ, RSSI for the auxiliary cell. The method according to claim 1,
Wherein the at least one processor is configured to determine an increase amount of the congestion window value and the reception window value based on an expected bandwidth increase value when activating the auxiliary cell. The method according to claim 1,
Wherein the at least one processor is configured to determine an increase amount of the congestion window value and the reception window value based on the channel congestion of the auxiliary cell. A communication method of an electronic device,
A TCP connection is established between the electronic device and the server using radio resources of a primary cell,
Obtaining information on at least one secondary cell available from the base station,
Determining a signal quality for the at least one auxiliary cell,
Wherein when it is determined that carrier aggregation of the main cell and the at least one auxiliary cell is possible as a result of the measurement of the signal quality, at least one of a congestion window value and a reception window value of a TCP connection between the electronic device and the server And changing one.

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